Comparison of the correlation signal of each spectrum of the grid BT-SETTL15 obtained with TExTRIS (color map) and the 2D posterior obtained with ForMoSA (gray contours). We also compare the normalized 1D posterior obtained with ForMoSA on the K band without the continuum (black line) with the normalized 1D pseudo-posteriors extracted from the correlation signal map (blue cross) and a χ² map (green cross) for the T_eff and the log(g) (top and right panel, respectively). The white rectangle corresponds to a nonconverged synthetic spectra.